The United States has more than 200,000 sites with contaminated groundwater and subsurface soils due to leaking underground storage tanks, industrial wastes, and accidental spills. These contaminated sites contain over 1.7 million gallons of chemical and foreign microbial waste; the ability to conduct subsurface remediation is essential for controlling and reducing potential spread of contaminants within an aquifer's watershed.
Subsurface remediation proves to be challenging because most sites require treatment of both groundwater and subsurface soils. Conventional methods for in-situ remediation include pump-and-treat, thermal desorption, use of surfactants, and air venting. Each method has benefits and limitations, but all of these methods require a long time, many months to years, before significant remediation is accomplished at a contaminated site.
Chemical oxidants are highly reactive gases and liquids that can be injected into the ground to remediate both groundwater and soils in-situ. Current oxidant delivery methods are effective in remediating recalcitrant compounds; however, these methods are costly, require high maintenance, and can be dangerous to workers. Examples of chemical oxidation hazards include contact with strong oxidizing solutions and acids, explosions, and worker injuries due to the use of more risky techniques such as direct-push injections for liquid delivery.
Thus there remains a need for a new and improved remediation system and a controlled release remediation composition or compositions that address the problems of conventional methods for in-situ remediation.